There was a solar flare blocking all communications all over the planet, as Zod just explained to Seg-El as the reason he cannot contact Lyta right then, in the next shot, it was shown that Dev-Em and Jayna-Zod were flying an skimmer in the outlands which is even more prone to be affected by solar flare. As it cannot be mechanical plane, it requires communications between its own various parts and also with ground control center, so it would not have been able to fly while the solar flare has been stalling all communications.